While the National Origins Act of 1924 imposed limits on immigration from much of the world, countries in the Western Hemisphere were exempt. American farmers and business owners who relied on migratory labor from neighboring Mexico lobbied to keep America’s southern border “open.” Workers regularly crossed in and out of the U.S. through its southern border at will. The Mexican Revolution prompted some migrants to settle more permanently in the U.S., and politicians from border states — particularly California — made unsuccessful attempts to include Mexico in the National Origins quotas. 

The National Origins Act did attempt to restrict border crossings from Mexico in another way: it authorized the creation of the U.S. Border Patrol. Recruited from existing law enforcement agencies, including the Texas Rangers, sheriffs’ departments, and customs inspectors, Border Patrol agents were armed officers tasked with “securing” the nation’s borders. The bulk of their enforcement power was directed at the southern border and often came with mistreatment, brutality, and humiliation, much of which has been directed towards migrants from Mexico ever since.